Inflatable spreader bars?

**cmoulder** · 03-09-2019, 11:53

I cut them with a Dremel cutting wheel and sand them off (by hand) even and smooth with 60 grit down to about 200 grit. Good enuf!

This 3K roll-wrapped stuff which I linked somewhere earlier is not like that cheap pultruded crap that splinters all over the place. Very easy to work with.

**cmoulder** · 03-09-2019, 12:31

Tested this morning with the hammock strung up fairly low over some soft, mushy snow. Per JB's suggestion, at the start of testing I put my trusty trekking pole at the head and the new UL spreader at the foot, then carefully sat on the hammock with full weight, gradually doing some small bounces to shock load a little, bounced ever more vigorously, then stretched out in the normal rest position. No worries, it didn't seem strained in the least.

Happy with that result, I put in the head-end spreader and repeated the process... again, no worries. I scooted over near the head end with all my weight in the "head pocket" area of the hammock and it still did not over-stress the spreader. Plucking the center of the spreader, it made a pleasant 'boing' and then quickly re-centered itself. VERY stable.

I was worried that the small, hollow 9/7mm tubes used on the tips might get crushed, however I wanted to see how they'd hold up without modification... they were fine, at least for this 45-minute 'ride'. If there is a problem observed later, it will be easy enough clean up any damage and put some 7mm CF rods in there.

So they were 2.5g over target weight, but not too shabby, lol.

This morning's test venue... (blurred out JB's proprietary bits):::

UL spreader bar in place:

UL spreader bar tip:

**autox** · 03-09-2019, 14:17

Congrats! Those look great!

So, asked and answered: no, it doesn't look like there's any potential weight savings in inflatable spreader bars.

I think this was your call in your first post on this thread.

**cmoulder** · 03-09-2019, 15:28

Originally Posted by autox

Congrats! Those look great!

So, asked and answered: no, it doesn't look like there's any potential weight savings in inflatable spreader bars.

I think this was your call in your first post on this thread.

lol, well that was certainly the long route to getting the answer, and sorry I derailed your thread like that train in The Fugitive, but I do thank you for the inspiration and motivation to follow through. I hope to test these on some actual overnights, so we'll see how they hold up.

It has been a fun project and also funny that I should make these since I'm not primarily a bridge guy, and wouldn't need them anyway even if I were since I'd use trekking poles.

OK, now somebody has got to try this with a Beryllium alloy... gonna get real spendy real quick.

**autox** · 03-09-2019, 21:07

Happy to have helped nudge things forward with a few questions. The thread drift was very educational.

One other quick thought on making bridges lighter - has anyone tried orienting the fabric on the bias, at 45 degrees? It might be a bit more comfortable as I imagine it will stretch and conform to your body a bit more, of you're not using an inflatable pad. More importantly, it will load both warp and weft fibers; with warp fibers oriented head to toe, they don't see much load so there's some dead weight there. Another way to approach this inefficiency would be lower denier warp than weft.

**cmoulder** · 03-10-2019, 07:47

Originally Posted by autox

Happy to have helped nudge things forward with a few questions. The thread drift was very educational.

One other quick thought on making bridges lighter - has anyone tried orienting the fabric on the bias, at 45 degrees? It might be a bit more comfortable as I imagine it will stretch and conform to your body a bit more, of you're not using an inflatable pad. More importantly, it will load both warp and weft fibers; with warp fibers oriented head to toe, they don't see much load so there's some dead weight there. Another way to approach this inefficiency would be lower denier warp than weft.

Cutting edge ideas there, and it'll be interesting to see what the fabric experts say. I don't know how much weight savings could be realized since bridges already use less material than GEs, and JB has used some quite (scary!) light materials. It is amazing to me that the current materials hold up as well as they do, such is the stress on those corners.

Additionally, with the new UL spreaders the total weight with JB's 1.6 Hexon prototype, including CLs, is 10.92 oz (309.7g) which is pretty darn good even for a hard-core gram weenie. Add some venom straps @1.8 oz and as is you've got a seriously light setup, right around 12.7 oz.

**cmoulder** · 03-10-2019, 08:28

Adding up the numbers....

**GreatBigDave** · 03-10-2019, 15:15

Swear word. Swear word. Swear word-swear word-swear word-swear word. Swear word; Swear word!

Dang!

**cmoulder** · 03-10-2019, 18:48

Originally Posted by GreatBigDave

Swear word. Swear word. Swear word-swear word-swear word-swear word. Swear word; Swear word!

Dang!

So that's good, right?

Well it certainly passed the first test, but let's see how it works out for an overnighter, and then multiple overnighters. I hope to sneak out for a quickie overnight this week, maybe tomorrow or Tue or Wed night.